Connecting-rod.



PATBNTED AUG. 16, 1904.

C. M. SPALDING. CONNBGTING ROD.y APPLICATION FILED FEB. 24, 1903.

No MODEL.

Fig.

Chester mpaldng. by M,;

UNITED STATES Patented August 16, 1904.

PATENT OFFICE.

CHESTER M. SPALDING, OF SCHENECTADY, NEV YORK, ASSIGNOR TO GENERALELECTRIC COMPANY, A CORPORATION OF NEW YORK.

ooNNECTlNe-ROD.

SPECIFICATION forming part of Letters Patent No. 767,772, dated August16, 1904.

Application filed February 24, 1903. Serial No. 144,653. (No model.) Y

To all whom it may concern: Y

Be it known that I, CHESTER M. SPALDING, a citizen of the United States,residing at Schenectady, county of Schenectady, State of New York, haveinvented certain new and usefulV ularly relates to such connecting-rodsas are used in air-compressors or the like.

In the application of electrically-driven aircompressors torailway-work, especially for use in air-brake systems, great diiiicultyand consequent inconvenience has been experienced due to the vibrationof the compressor while operating. In air-compressors in which thedriving-motor is directly connected by means of a connecting-rod to theplunger or piston of the air-compressor there is considerable strain on'the connections between the crank-pin on the armature-shaft and theconnecting-rod, as said rod reciprocates while the compressor is inaction. Consequently there is considerable wear in the bearing in therod in which the said pin operates. This wear soon causes a certainamount of lost motion between the pin and the connectingrod, allowing afree movement of said pin in its bearing at each end or approximately ateach end of the stroke of the compressor-piston, thereby causingconsiderable vibration and noise. .If it is attempted to prevent thislost motion by fitting the crank-pin very tightly in its bearing whenthe compressor is'first assembled, there will be a gripping and clampingaction of the different parts of said bearing after it has been runninga short time, due to frictional heating. The same statements applyequally to the other end of the connecting-rod, which carries a bearingin which a pin or shaft which is fastened to the piston of thecompressor operates.

The object of my invention is to reduce the vibration due to the causesabove enumerated, thereby reducing the noise and increasing the efciencyand the smoothness with which the compressor may be run.

In the accompanying drawings, which illustrate the preferred embodimentof my invention, Figure l represents a longitudinal section through adouble-acting direct-connected air-compressor driven by an electric m0-tor and to which my improved connectingrod is applied. Fig. 2 is aperspective view of the connecting-rod. Fig. 3 is a section through thesaid connecting-rod on the line 3 3 of Fig. 2, and Fig. 4 is a detail ofthe connecting-rod.

Referring now to Fig. l, A represents the casing of a motor of theinclosed type. Fastened to said casing A are two cylinders Cr of theair-compressor, the said cylinders being provided with externalcircumferential ribs g to radiate the heat of the air compressed in thecylinders. rPhe two cylinders are in line with each other, their axesbeing at right angles to the axis of the armature-shaft C andintersecting it at a point beyond the end of the journal C about halfthe length of the crank-pin D. 1n each cylinder is a piston H, the twobeing connected by upper and lower tie-bars 7L, preferably cast integralwith the pistons. One of said pistons H carries the wristpin L, whoseaxis is transverse to that of said piston and is parallel to the axis ofthe armature-shaft. The connecting-rod P is pivotally connected at oneend to said wrist-pin /L anfv at the other end to the crank-pin D. Theheads G' are preferably secured by means of the screw-bolts G2. Eachhead carries one or more inlet-valve chambers N and one or moreoutlet-valve chambers N. The air drawn in through the inlet-valves andcompressed in the cylinders flows through the outlet-valves into apassage K and thence to a delivery pipe.

The specific form of air-compressor herein shown and described does notconstitute any part of my invention, since the same forms thesubject-matter of a copending application of Asa F. Batchelder, SerialNo. 74,244, filed September 3, 1901.

To take up the wear between the bearings in which the crank-pin D andthe wrist-pin /a operate and said pins and at the same time preventtight bearings due to frictional heating, I have provided theconnecting-rod P with self-adjusting and yielding bearings. The saidcoimecting-rod is made up of the rigid member or strut O and thestirrups or straps It and It. The spceilic construction of theconnecting-rod is more clearly shown in Figs. 2 and 3, upon aninspection of which it will be seen that the stirrup It is formed withan extension or loop r, which is inter-linked with the strut or rigidmember O. The strap or stirrup R/ is also formed with an extension orloop fr, which in this case is bifurcated in order to receive theextension or loop fr. The said loop r2 is also interlinked with therigid member O, the three parts R, R, and O being connected together inthe same manner in which the links of chain are connected together. Themember O is divided longitudinally into two parts, which are rivetedtogether when the connecting-rod is assembled. Located between the innerends lr and r" of the loops or extensions of the stirrupsR and R,respectively, is a compressible spring' S, which is held in place bycentering-pieces formed integral with or otherwise fastened to saidstirrups. The centering-piece W, which is mounted on the inner end I/ofthe extension y' of the stirrup R, is shown in Figs. 3 and 4f. It willthus be seen that the spring S tends to separate the inner ends r andr4, and consequently to draw together the outer ends of the stirrups orstraps R and R, respectively, whenever the bearings in which the pins Dand L'" operate are worn away by use.

It will be seen that as the air is compressed in the left-hand cylinderGr, Fig. l, the thrust of the piston H is taken directly on the strut O.New if this connecting-rod is applied to a direct-connectedsingle-acting air-col'npressor a comparatively small amount of pullwould be exerted on the spring S during either the forward or returnstroke of said piston H. Under such conditions a very small spring isall that is necessary to take up automatically the wear in the bearings.In. applying' the invention to the double-acting air-compressor shown inFig. l, however, it is necessary to make the spring S heavy and strongenough y to take the direct thrust of the piston H at the right-hand endof the air-compressor when the air is being compressed in the cylinder Gat that end of the compressor. rIhe spring S should be made so strongthat the distance between the axes of the pins D and /z/, respectively,would not be changed in any part of the forward or return strokes of thepiston or pistons.

Although I have shown and described my invention as applied to aspecific form of aircompressor, I do not wish to limit the applicationof said invention to such a device, since the improved connecting-rod isclearly applicable to all kinds of engines or machines in which it isdesirable -to reduce the vibration caused by lost motion in the bearingsof the connectingrod. Furthermore, many modifications of theconstruction herein shown may be made without departing from the spiritand scope of my invention, and in the appended claims I aim to cover allsuch modifications.

Vhat I claim as new, and desire to secure by Letters Patent of theUnited States, is-

y 1. A connectingred comprising a rigid member, relatively adjustablemembers adapted to coact with the said rigid member to form bearings forshafts or pins at the ends of said rigid member, anda spring connectionbetween said adjustable members.

2. A connecting rod comprising a rigid member, a relatively adjustablemember at each end of said rigid member which forms with the end of saidrigid member a bearing for a pin or shaft, and a spring between saidadjustable members for the purpose of making said bearings yieldinglyself-adj usting.

3. A connectingrod comprising a rigid strut, a stirrup or strap at eachend of said strut which forms with the end of said strut a bearing for apin or shaft, and a spring between said stirrups for the purpose ofautomatically taking up the wear in said bearings.

4. A connecting rod comprising' a rigid strut in the form of a link, twostraps er stirrups intel-linked with said strut each of said straps orstirrups forming with the end of said strutv a bearing for a pin orshaft, and yielding means normally tending to draw said straps towardthe ends of said strut.

A connectingrod comprising a rigid strut in the form of a link, twostraps or stirrups nterlinked with said strut each of said straps orstirrups forming with the end of said struta bearing for a pin or shaft,and a spring located between the inner ends of said interlinked strapsor stirrups for the purpose of automatically taking up the wear in saidbearings.

In witness whereof I have hereunto set my hand this 20th day ofFebruary, 1903.

CHESTER M. SPALDING. WVitnesses:

BENJAMIN B. HULL, HELEN ORFoRD.

ICO

